Micromeritics AccuPyc 1330 Operator's Manual page 9

AccuPyc 1330
In addition to analysis, there are two other automatic operations performed by
the pycnometer: calibration and transducer zero reset.
Analysis measures sample volume, from which density can be derived auto-
matically if sample weight has been entered. The unit comes pre-programmed
with default conditions and ready to perform analyses. It can be easily repro-
grammed to meet your specific needs. You can modify your own analyses by
entering the following parameters: number of purges, purge fill pressure, num-
ber of runs, run fill pressure, equilibration rate, and run precision. The run
precision option allows early termination of the analysis if the last five runs
are all within a user-specified tolerance. By modifying these parameters, you
retain control over the two main sections of the analysis: purge and run.
A purge is used strictly for sample clean up and air and moisture removal
from the chamber's inside. It is accomplished by closing off the pycnometer
block and filling the cell chamber to the designated purge fill pressure. The
chambers are then vented to atmosphere, resulting in elimination of water va-
por or other contaminants. A run is used for collecting the precise, accurate
data used in report calculations.
Calibration is used to determine the size of the cell and expansion chambers
within the instrument. After calibration, the cell and expansion chamber vol-
umes are automatically stored in the set-up parameters.
The zero function is used to calculate a new zero pressure offset. It is meas-
ured when the system is at atmospheric pressure and thermal equilibrium and
is subtracted from all subsequent pressure readings in order to obtain a true
gauge pressure.
September 1996
Cell Chamber
Expansion Chamber
Expansion
Fill Valve
Valve Indicator
Indicator
Figure 1-2. Schematic Diagram
Equipment Description
Vent Valve
Indicator
1-3